Thread: subneting

  1. #1
    Set Apart -- jrahhali's Avatar
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    subneting

    i want to use 4 subnets but that means i will have to create 6 of them. in able to do this, do i have to assign the IP's to only 4 of the 6 subnets? is there any other way i can do this?

  2. #2
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    No, if you want to split a block of IPs (im assuming you have a class C) for example, you control the block 192.168.1.0-255, if you wanted to split that into 4 subnets you could use a subnet mask of 255.255.255.192, and that would split it into blocks of 62 addresses. 192.168.1.1-63, 192.168.1.64-127, 192.168.1.128-191, 192.168.1.192-254.

    Subnet Address: 192.168.1.0
    Subnet Mask: 255.255.255.192
    Subnet Bits: 26
    Host Bits: 6
    Possible Number of Subnets: 4
    Hosts per Subnet: 62

    Happy subnetting, msg me, mail me, or just reply if i didnt answer your question.

  3. #3
    Set Apart -- jrahhali's Avatar
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    ahhh, that clears up a lot for me. thanks.
    One more question though.

    say i want 5 subnets now instead of 4. i can't use the netmask of 255.255.255.192 (26 bit) because that would make 4 subnets not 5. so i have to use 255.255.255.224 (27 bit). The problem is that this netmask makes 8 subnets available when i only want to use 5.

    Is there any way just to make 5 subnets available? and if not would i just assign IP's to 5 of the 8? and if this is the case, what happens to the 3 subnets that are left over.

    If i am completely mistaken about what am trying to ask then please try to correct me

  4. #4
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    You are correct, you would have to create 8 subnets and just use 5. Yes subnetting isnt very flexable about this, and it does cause the waste of quite a few IPs. Wasted blocks of IPs causes problems such as the now critical shortage of unowned IPs. I wish the system were better but this is what we get to work with. Why the interest? Practical use for subnets, or just studying up for a ccna test or something? Good luck, whichever your goal is.

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